An increasing number of common household items are evolving into computing machines capable of network communication. The goal of such an evolution is to allow appliances throughout a home to communicate with one another so that the user can simplify his or her lifestyle. For example, many common household items, including ovens, microwaves, video devices, radios and alarm clocks each contain a time display. However, because such appliances cannot currently communicate with one another, the user is forced to set the correct time on each appliance. Inter-appliance communication would allow a single appliance to share the correct time with all of the other appliances, minimizing the effort on the part of the user. Such efficiencies, however, require creating and managing a communications network connected to many different appliances.
To ease the burden of setting up a communication-capable appliance and integrating it into such a network, a number of technologies and protocols have been developed which allow appliances to configure themselves. One such technology is known as Universal Plug and Play (UPnP) and defines a mechanism by which an appliance can automatically learn of other appliances and integrate itself into the network. The UPnP architecture defines two categories for appliances: a “device” category, containing those appliances which can receive instructions and perform functions, and a “control point” category for those appliances which can send instructions and thereby control devices. A UPnP device can advertise the “services” it is capable of performing by broadcasting a message throughout the communication network to which it is attached. The message containing the services can be detected by a UPnP control point and, if the control point is interested in the services exposed by the device, it can query the device for further information regarding those services and learn how to control those services.
From the perspective of the user, UPnP devices and control points are setup-free: the user merely plugs them into the communication network, and the appliances configure themselves. Thus, a user having a UPnP compliant oven, microwave, video device, radio and alarm clock need not spend the time and effort to determine the correct time and set the time on each appliance. Instead the user can simply attach a control point, such as a personal computer, and the control point will learn of each device connected to the communication network. A single instruction from the user to a control point can be used to set the correct time on each device, saving the user from the burden of setting each separately.
However, the current UPnP implementation does not provide any mechanism by which a device or control point can automatically tune or filter the information it displays to the user. For example, a device is limited by its functionality to displaying whatever information it is provided by a control point. Thus, an LCD picture frame, for example, will display all of the pictures sent to it by a control point, and a speaker, such as a radio or stereo system, will play whatever audio data it receives from a control point. A control point will allow user control over the pictures sent to the picture frame or the audio sent to the speaker, for example, but it requires the user to perform the filtering. Thus, a user seeking to send one set of pictures to an electronic picture frame in a home office, and another set to an electronic picture frame in a family room must explicitly define each set at the control point and direct each set to a particular picture frame. If the user subsequently moves the picture frame from the home office into the bedroom, the user is forced to explicitly define a new picture set for the bedroom at the control point, and direct it to the picture frame now located there. Similarly, if the user has a personal computer set up as a control point, with a broadband connection to a network such as the Internet, through which the user receives digital radio stations, the user will be forced to select the radio stations played by the speaker at the control point instead of at the speaker. Ultimately, the user is continually forced to perform any tuning of the content presented on their own and only at the control point.